The present invention relates to a wheel suspension for a non-driven steerable vehicle wheel, comprising an axle member, which at each end has a conical through-bore, which holds a conical central portion of a kingpin, which is provided with kingpin ends extending outside the bore into the member, and a spindle unit, having, firstly, spaced upper and lower spindle ears holding bearings into which the kingpin ends extend and of which the upper bearing is a roller bearing and the lower bearing is a journal bearing, and, secondly, an axle end on which a wheel hub is intended to be mounted.
The most common type of steering knuckle arrangement for trucks has the spindle unit mounted in a taper roller bearing at the upper end of the kingpin and a journal bearing at its lower end. The upper bearing takes up both axial and radial forces while the lower bearing only takes up radial forces. In such a spindle bearing, the axial force on the upper bearing is load-dependent, i.e. the axial load on the bearing varies with the total weight of the vehicle. When taking a curve, the radial forces on the lower bearing from the kingpin will be such that they strive to tip the lower bearing bushing in its seat in the lower spindle ear. Since the bushing is forced into its seat and the kingpin is mounted with the minimum possible play in the bushing, the bushing cannot even out the force couples which apply an asymmetric load. This results in the upper and lower areas of the bearing race being subjected to radial forces and greater wear than the middle portion, and this in turn can lead to gaps occurring after a relatively short time when driving with heavy loads on winding roads.